Reproductive biology of the Indian mackerel Rastrelliger kanagurta (Cuvier, 1816) from the Mahout coast, Sultanate of Oman

Abstract

A study on the reproductive biology of the Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816) was made from the Arabian Sea coast of Mahout, Oman for a period of two years from September 2007 to August 2009. Occurrence of spent gonads during September-October and January-February during 2007-08 and from December to April and August during 2008-09 indicated difference in spawning periodicity between the years. Individual fish appeared to spawn for the second time in a year. The monthly Kn values in both the sexes could not be related to spawning activity. The length at first maturity (Lm) for males and females were estimated at 252 and 257 mm respectively. Females were dominant than males in the catches and the annual sex-ratios differed significantly. The fecundity of females varied between 64,024 and 151,844 eggs with an average fecundity of 98,273 eggs. As the estimated Lm of R. kanagurta is lower than the size at capture along the Mahout coast, there is no management concern at present.